An interventional study of Transcranial Ultrasound Device in Hereditary Haemorrhagic Telangiectasia, PFO - Patent Foramen Ovale and Pulmonary Arteriovenous Malformation, sponsored by St. Antonius Hospital. Recruiting at 1 site in Netherlands. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-02-17.
Sponsored by St. Antonius Hospital · Not applicable, Interventional, and Diagnostic
The goal of this clinical trial is to learn how well the SONAS ultrasound device can detect right-to-left shunts of adults with hereditary hemorrhagic telangiectasia (HHT) who are already scheduled for a contrast bubble echocardiogram (TTCE). The main questions it aims to answer are:
Participants will wear a headband with the SONAS device on the head while they undergo their routine TTCE bubble test. They will receive the usual contrast (agitated saline) through a vein, and both SONAS and TTCE signals will be recorded at the same time. There will be one examination in rest, and one during a breathing exercise (the Valsalva manoeuvre).
This study is being done to find out whether a new ultrasound device called SONAS can safely and reliably detect "right-to-left shunts" in people with hereditary hemorrhagic telangiectasia (HHT). Right-to-left shunts are abnormal connections between blood vessels that allow blood to bypass the lungs and go directly from the right side of the heart to the left side. This can increase the risk of problems such as stroke or brain abscess. Today, these shunts are usually found with a "bubble heart ultrasound" (TTCE), which needs experienced staff and can be time-consuming. SONAS is a small, portable device that detects blood flow signals in the brain after a bubble injection and may offer a simpler way to detect these shunts.
In this study, all participants are are already scheduled to have a bubble heart ultrasound as part of their regular care. The study adds the SONAS device on top of this routine test. During the procedure, a soft headband with small ultrasound sensors is placed in frond of the ears on both sides of the head. At the same time, the standard bubble test is done: normal saline mixed with a small amount of the participant's blood and some air is injected into a vein, and the heart is imaged with ultrasound. Participants will be asked to perform a straining manoeuvre (called a Valsalva) to see if this makes a shunt more visible. While this is happening, SONAS continuously records signals from the brain that show when the bubbles pass through.
There will be a comparison between what SONAS shows with what the standard heart ultrasound shows. By comparing these results, the researchers want to see how closely the SONAS score matches the standard test and whether certain SONAS outcomes indicate a clinically important shunt. They will also look at the timing and pattern of the bubble signals to explore whether SONAS can help tell the difference between shunts that come from the heart and those that come from the lungs. The study does not change any decisions about diagnosis or treatment: all medical decisions remain based on the usual heart ultrasound and other standard tests.
Throughout the procedure, the safety and comfort of participants are closely monitored. SONAS does not deliver any contrast or radiation. All problems or unusual events that occur during or shortly after the combined test are recorded. The information collected in this study will help determine whether SONAS is a practical, safe, and useful tool to support or simplify screening for right-to-left shunts.
99 studies on the registry are indexed under Telangiectasia, Hereditary Hemorrhagic; 23 are open to participants now.
This study's planned enrollment of 40 is above the median of 33 across 59 interventional studies indexed under Telangiectasia, Hereditary Hemorrhagic.
Browse Telangiectasia, Hereditary Hemorrhagic studies →St. Antonius Hospital is the lead sponsor of 94 studies on the registry; 28 are open to participants now.
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Exclusion Criteria:
This study has a single arm in which all participants undergo SONAS monitoring during a standard contrast echocardiogram (transthoracic contrast echocardiography). In this arm, adults with (possible) hereditary hemorrhagic telangiectasia or PFO who are already scheduled for a clinically indicated bubble echocardiogram have a headband with the SONAS ultrasound device examination. Agitated saline is injected into a vein as part of usual care, and the heart is imaged with echocardiography while SONAS simultaneously records ultrasound signals from the brain.
Device: Transcranial Ultrasound Device
The intervention is the SONAS ultrasound device used during a routine bubble echocardiogram. A battery-powered unit connects to a headset with two ultrasound sensors placed in front of the ears. The device does not deliver contrast or drugs; it records ultrasound signals in the brain while standard agitated saline is injected and the heart is imaged. SONAS analyzes bubble-related signals and calculates a numeric score to evaluate right-to-left shunts without changing the usual echocardiography protocol.
Also known as: SONAS, Foqus
Capability of detecting Right-to-Left Shunts
Device capability of detecting High Intensity Transient Signals (HITS) using SONAS in presence of RLS, as confirmed by reference method TTCE. SONAS output is expressed as maximum HITS Density Score (0-100%). TTCE outcome is assessed by RLS grade (0-3), maximum microbubble count in left ventricle, and corrected change in echo density.
Time frame: Periprocedurally
Diagnostic accuracy
Diagnostic accuracy (sensitivity and specificity) of SONAS for detection of clinically significant RLS (≥grade 2 on TTCE) at different HITS Density Score thresholds.
Time frame: Periprocedurally
Distinguishing intracardiac from pulmonary Right-to-Left Shunts
SONAS capability to distinguish intracardiac from pulmonary RLS based on time delay between contrast administration and first HITS occurrence, and difference in HITS Density Score between rest and Valsalva maneuver.
Time frame: Periprocedurally
Test-retest reliability of SONAS for HITS assessment
Test-retest reliability of SONAS for HITS assessment using Intraclass Correlation Coefficient.
Time frame: Periprocedurally
Plan to share: Yes — All anonymized Individual Patient Data that underlie results in the publication.
Supporting information: Study protocol
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